<p style="text-align: justify; line-height: 200%;"><strong><span lang="EN">Introduction:</span></strong><span lang="EN"> We evaluated the association between sleep duration and neurocognitive function in middle-aged to older (45-74 years) Hispanic/Latino adults (n=8059). </span></p><p style="text-align: justify; line-height: 200%;"><strong><span lang="EN">Methods:</span></strong><span lang="EN"> Cross-sectional analysis from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). This community-based cohort recruited participants in four US urban areas using a probability design (2008-2011). Self-reported sleep duration was calculated as a weighted average of the difference between habitual wake and bedtimes assessed by separate questions for weekdays and weekends. Neurocognitive function was measured with standardized scores for Word Fluency (WF), Brief-Spanish English Verbal learning test (B-SEVLT) and Digit Symbol Substitution (DSS) tests. We performed multivariable regression analysis accounting for the complex design and sampling weights, and adjusted for confounders. We tested splines and higher polynomial functional forms to account for the curvilinear inverted U-shaped association between sleep duration and neurocognitive function scores in adults aged 45-74 years. </span></p><p style="text-align: justify; line-height: 200%;"><strong><span lang="EN">Results:</span></strong><span lang="EN"> The mean age was 56 years, 55% were women and 41% had less than high-school education. Average sleep duration was 7.8±1.7 hours. We found an association between the quadratic term for sleep duration and WF, (β = -0.010; p &lt;0.05), B-SEVLT-sum (β= -0.009; p &lt;0.05), and the DSS (β = -0.009; p &lt;0.01), with no association with B-SEVLT-delayed-recall. Those with intermediate sleep duration had the best neurocognitive function, </span>while long sleepers had worse <span style="mso-bidi-font-size: 11.0pt; line-height: 200%; mso-font-kerning: 11.0pt; mso-bidi-language: EN-US;">neurocognitive</span> function <span lang="EN">adjusting for demographic, behavioral, medical and sleep covariates. </span></p><p>&nbsp;</p><p style="text-align: justify; line-height: 200%;"><strong><span lang="EN">Conclusion:</span></strong><span lang="EN"> An inverted U-shaped association was observed between sleep duration and neurocognitive function such </span>that those with longer sleep durations had the worse <span style="mso-bidi-font-size: 11.0pt; line-height: 200%; mso-font-kerning: 11.0pt; mso-bidi-language: EN-US;">neurocognitive</span> scores.&nbsp;&nbsp;</p>